Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Current Assets:
Cash and cash equivalents	$ 28,559	$ 7,999
Short-term investments	18,351	8,182
Accounts receivable, net of allowance for doubtful accounts of $86 and $47 in 2013 and 2012, respectively	14,164	13,054
Inventories	26,266	23,779
Prepaid expenses and other current assets	1,603	3,110
Deferred income taxes	1,376	623
Total Current Assets	90,319	56,747
Long-term investments	10,069	28,433
Property, Plant and Equipment	130,504	124,180
Less accumulated depreciation and amortization	72,176	64,912
Property plant and equipment net	58,328	59,268
Other Assets and Deferred Charges:
Patents and licenses, net of accumulated amortization of $11,032 and $10,853 in 2013 and 2012, respectively	2,808	837
Goodwill	9,730	9,730
Other	812	795
Prepaid Expense and Other Assets, Noncurrent, Total	13,350	11,362
Total Assets	172,066	155,810
Current Liabilities:
Accounts payable	4,088	3,843
Accrued liabilities	4,423	2,900
Accrued income and other taxes	853	465
Total Current Liabilities	9,364	7,208
Line of credit
Other Liabilities and Deferred Credits:
Deferred income taxes	12,062	12,232
Other	1,646	1,542
Liabilities Noncurrent	13,708	13,774
Total Liabilities	23,072	20,982
Commitments and Contingencies
Stockholders' Equity:
Common stock, par value $.10 per share, authorized 10,000 shares, issued 3,420 shares	342	342
Additional paid-in capital	31,592	29,998
Retained earnings	174,362	152,630
Treasury shares, 1,428 shares in 2013 and 1,399 shares in 2012, at cost	(57,302)	(48,142)
Total Stockholders' Equity	148,994	134,828
Total Liabilities and Stockholders' Equity	$ 172,066	$ 155,810